Dennis and Dee's estranged father, Frank Reynolds, returns to town to reconnect with his kids. They don't want anything to do with him, but Frank likes hanging with Charlie and Mac. Meanwhile, Charlie gets hit by Dennis's car (accidentally, of course) and needs to use a wheelchair. The gang soon discovers that this isn't all that bad.
The gang's new neighbor from Israel threatens to shut down Paddy's, and he has the law on his side. So the gang must "get creative." This means jihad. And Frank's wife, Barbara, returns from vacation, but absence certainly didn't make her heart grow fonder.
Driven to distraction by their dad, Dennis and Dee quit Paddy's and decide to go on welfare. Back at the bar, Frank is driving Mac and Charlie crazy. He's also beginning to treat them like sons.
Barbara sleeps with Mac to arouse Frank's jealousy, so Dennis decides to seduce Mac's mom as payback. And Frank's decision to put Charlie in charge at the bar prompts an orgy of backstabbing and double-dealing, with sex as the weapon of choice.
After she's mugged, Dee takes boxing lessons from ex-pug Frank, who runs into an old nemesis at the gym. Meanwhile, Mac and Dennis enter Charlie in an underground street-fight match with hopes of making some money. And both Dee and Charlie need help, which they find in a pill bottle.
The gang must perform community service after their "mishap" gets them arrested for arson. While fulfilling his duty, Charlie discovers that he has something in common with the coffee-shop waitress. Meanwhile, Frank's attempt to bond with Dennis backfires.
The Madonna of Paddy's? The gang seeks financial salvation when a leaky pipe at Paddy's causes a water stain on the wall that resembles the Virgin Mary. Meanwhile, Dee has an awkward reunion with a priest who had a crush on her in high school.
Frank offers the gang his political wisdom, which unsurprisingly involves bribery. Then Dennis decides to run for office himself.
Let freedom ring at Paddy's! After an argument about constitutional rights and smoking in the bar, Mac and Dennis decide to lift all behavioral restrictions, and Paddy's soon goes wild. Meanwhile, Charlie and Dee head off to an antitobacco demonstration.
Dee receives e-mails from a man who claims to be her father, so she confronts Frank and Barbara to find out what's up. Meanwhile, Mac seeks out his own dad, who's in prison.
